Danny Welbeck left the Etihad Stadium wearing a protective boot on his ankle and Ferguson was unhappy with De Jong's challenge and the manner in which Mancini was talking to fourth official Mike Jones.

'He refereed the game,' said Ferguson.

'He was out on that touchline the whole game haranguing the referee, the fourth official and the linesmen.

'The minute I come off the bench for a bad tackle by De Jong on Welbeck, he was out again.

'He can't have it both ways. He's been complaining about referees this season but he won't be complaining tonight that's for sure.'

Mancini attempted to play down the spat, insisting it was just the tension of the moment that got the better of his opposite number.

'He doesn't talk with the referee or fourth official? Never?' said the Italian.

'I didn't speak with him (Ferguson). He turned towards me and said something.

'For me it is no problem. I can understand.

'I didn't say anything against him. I was only talking to the fourth official.'

All's well that ends well: Ferguson and Mancini shake hands at full time after City's crucial victory

Ferguson might reflect that his players would have been better served if they had shown a similar amount of fight.

Instead, the visitors were poor, having adopted a policy of containment, and had no answer once Kompany had powered home David Silva's corner.

'It was a bad time to lose a goal,' said Ferguson.

'It gave them the foothold in terms of just playing out the game - typical Italian, brought three defenders on and played counter-attack.

'But we didn't test the goalkeeper so we can't blame [anyone else], we can only blame ourselves really.'

Down and out: Manchester United are faced with losing the Premier League title to their bitter rivals

The evening was given a surreal air when pop superstar and celebrity City fan Liam Gallagher burst into the media room after Mancini had given his post-match observations to announce: 'Ferguson must have been on the whisky," and: "I love Mancini, he is nearly as cool as me.'

It was certainly more humorous than Mancini, who despite his side's second league double over United in 42 years taking them top on goal difference with just two games left, continued to insist the Red Devils are favourites to win the title.

'United are the favourites,' he said.

'They have easy games. They play against Swansea and Sunderland. They are strong teams but at this moment, for United they will be easy.

'We have two strong games, Newcastle and QPR. One plays for Champions League, the other for relegation.

'It is important that we are on the top now but it is more important to be there after May 13.'

Unbridled joy: Vincent Kompany scores the only goal of the game (above) and celebrates (below)

Momentum is with City though after they wiped out an eight-point deficit in the space of four games.

'Football is crazy,' he said.

'It is important to always believe in yourself when you have a bad moment.

'We were on the top for 28 games and I think we deserve another chance.

'But it is not finished. If we think it is finished, we will be making a big mistake.'

Ferguson must now hope for a favour from Newcastle at the Sports Direct Arena next Sunday, and then that his side take advantage by beating Swansea at Old Trafford.

Even with the Magpies flying high towards the top of the table, it seems like a forlorn hope.

And if City do emerge win their first championship since 1968, Ferguson will be able to pinpoint when it all went wrong.

'You can look back at all sorts of games but you've got to look at the Everton one,' he said.

'That was a ridiculous performance for the last seven minutes to lose two goals. That's maybe cost us the league.

'We know we need to win two games of football; that's another way of looking at it. Of course, we're certainly not in the driving seat any more.'

And it seems the result was not the only negative aspect of the night for United as Welbeck left the stadium with his ankle in a protective cast, which could have dire consequences, not only for his club but potentially England's Euro 2012 campaign.